I have invoiced a client for stock but they have changed their mind. They have not paid and I would like to know how to delete the invoice

Glad to have you here in the Community, @CLaire1.

I can help you delete the invoice in QuickBooks Online (QBO). We can do it by going to the Sales menu in your QBO account.

Here's how:

1. Go to the Sales menu.
2. Click Invoices.
3. Choose the invoice that you want to delete.
4. Under Action, click the drop-down arrow and then choose Delete.
5. Click Yes to confirm.

I've also added this article about customizing invoices and sales receipts in QBO: Customise invoices, quotes, and sales receipts.

Leave me a comment below if you have other questions. I'm always here to help. Take care!